Table Of Contents

Preface

Changes to This Document

Obtaining Documentation and Submitting a Service Request

Preface

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This document describes the Cisco IOS XR Quality of Service (QoS) feature for prioritizing traffic flow and providing preferential forwarding for higher-priority packets. The QoS techniques described include allocating bandwidth, improving loss characteristics, avoiding and managing network congestion, metering network traffic, and setting traffic-flow priorities across the network.

For QoS command descriptions, usage guidelines, and examples, refer to the Cisco IOS XR Modular Quality of Service Command Reference for the Cisco XR 12000 Series Router.

The preface contains the following sections:

•Changes to This Document

•Obtaining Documentation and Submitting a Service Request

Changes to This Document

The following table lists the technical changes made to this document.

Table 1 Changes to This Document

Release	Revision	Date	Change Summary
Cisco IOS XR 3.9	OL-20389-01	December, 2009	Initial release of this document.
Cisco IOS XR 3.9	OL-20389-02	March, 2010	In the "Configuring Modular Quality of Service Packet Classification on Cisco IOS XR Software," module: •Added to the description of the ACL Deny feature to clarify why you might need it. •Added the current behavior, which is to reject any ACL deny statements and display a warning message unless the ACL Deny feature is configured (CSCtc30846). •Corrected the configuration steps for "Applying the Route Policy to BGP." Removed the route-policy command, added the address-family and table-policy commands.
Cisco IOS XR 3.9	OL-20389-03	May, 2010	In the "Modular Quality of Service Overview on Cisco IOS XR Software," module: •Revised the Fabric QoS overview In the "Configuring Modular Quality of Service Packet Classification on Cisco IOS XR Software," module: •Added features that were introudced in Cisco IOS XR release 3.8: –Enhanced Hierarchical Ingress Policing –Policer Granularity •Removed the match not option and match protocol commandfrom configuration examples—they are not supported. •Removed match protocol, match destination-address mac, match source-address mac commands from "Configuring a Traffic Class"—they are not supported. •Removed a restriction that match-any is the only match option supported in traffic classes. •Corrected the number of classes supported in a traffic policy from 512 to 1000. •Removed a reference to SRP —it is not supported. •Removed restrictions stating that class maps with multiple ACLs of the same type are not supported—they are supported. •Replaced "bytes" with "packets" for the unit argument of the queue-limit commandin a configuration example. •Added a couple missing WRED parameters to the three-level hierarchical traffic policy configuration example. In the "Configuring Modular Quality of Service Packet Congestion Management on Cisco IOS XR Software," module: •Corrected the class scale upper limit in the feature history table. •Corrected examples: –Traffic shaping for an input interface –Traffic policing for a bundled interface –All in the multiple action set examples In the "Configuring Fabric Quality of Service Policies and Classes on Cisco IOS XR Software," module: •Revised the module to make it platform-specific for the Cisco XR 12000 Series Router.

Obtaining Documentation and Submitting a Service Request

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http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html

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